This moves the configure-generated parts of Makefile.common to a
separate (generated) Makefile, allowing Makefile.common to be a normal
Makefile.
OCaml's build system Makefile's now include Makefile.build_config (which
itself includes Makefile.config) but Makefile.config is still installed
as before. This allows configure to generate variables which are
specific to the build process and are not intended to be exported to the
installation.
I frequently get (parallel) build failures due to wrong dependencies
causing compilation failures in some otherlibs/ subdirectory. When
that happens, my workflow is to go to that subdirectory, run 'make
clean', and then compile again. But then another subdirectory is
broken for the same reason...
This otherlibs/Makefile provides a 'clean' target that will run clean
in all subdirectories (all the ones selected to be built at
configure-time), as well as 'all', 'allopt', 'partialclean' targets
that similarly dispatch to all subdirectories.
This is exactly the logic already present in the 'otherlibraries*'
targets of the root Makefile, except more fun with Make-style generic
functions.
This file is meant to be included by the per-directory makefiles
of otherlibs/*/Makefile; its target cannot be run directly from
otherlibs/. We would like to propose targets from otherlibs/,
in a new Makefile.
In order to prepare the transition to autoconf, this commit moves the
configuration Makefile out of the config directory which will disappear
and gives it the name it will have once intstalled, namely Makefile.config.
Some Makefiles were using export to set OCAML_FLEXLINK "globally" while
others set a variable FLEXLINK_ENV and set the environment explicitly.
All Makefiles now use FLEXLINK_ENV and also only invoke it on linking
commands (rather than, for example, all invocations of ocamlopt).
This commit renames a few C compiler related build variables so that
they are reserved for the build system. They will then be re-introduced,
but this time as user varialbes whose value can be freely customized
when compiling the package, without risking to conflict with those
command-line flags that are required by the build system itself.
Here are the variables this commit renames:
- CFLAGS -> OC_CFLAGS
- CPPFLAGS -> OC_CPPFLAGS
- LDFLAGS -> OC_LDFLAGS
Note: before this commit the compilation of scheduler.c in
otherlibs/threads was relying on make's implicit rule to compile C files.
Since this commit stops using the standard variables for flags,
it is necessary to introduce an explicit rule to compile C files
and that makes use of the newly introduced variables.
Some makefiles (lex, stdlib, otherlibs) would only offer allopt, while
others (ocamldoc, tools) only offered opt.opt. It is inconvenient to
have to remember which target name to use while going through various
repositories.
I can observe weird performance bottlenecks on my machine caused by
the use of 'cp' in the 'install' scripts of OCaml. When installing
into a directory that is already populated by an existing
installation, 'make install' can routinely take 10s on my machine¹. After this
change it reliably takes 1.5s, independently of whether the
destination is already populated or not.
¹: a brtfs filesystem on an old-ish SSD
Why I care
----------
An extra 10s delay due to 'make install' can be noticeable in tight
change-build-install-test feedback loops for a compiler change where
we change the compiler, have a fast 'make world.opt' due to
incremental builds, install the change and test it -- possibly after
installing a couple opam packages, which can be fairly quick.
Partial diagnosis
-----------------
The performance issue seems to be caused by the fact that 'cp' (at
least the GNU coreutils version), when the file already exists,
replaces it by opening it in writeonly+truncate mode and writing the
file content ('strace' shows that the delay is caused within an
'openat' call). In particular, using the --remove-destination option
(which changes 'cp' to just remove the destination file before
copying) removes the performance issue, but this option seems missing
from the BSD/OSX 'cp' so it could cause portability issue.
Change
------
The present commit rewrites the 'install' targets of all Makefiles to
use the 'install' command instead. 'install' by default gives
executable-like permission to the destination file, instead of reusing
the source file's permissions, so we specify manually the permission
modes, depending on whether the installed file is an executable (or
dynamically-linked library) or just data (including other compiled
object files).
Testing
-------
I checked manually that the permissions of the installed files are
identical to the ones of the current 'cp'-using targets, except for
some '.mli' file in middle_end which currently have +x bits enabled
for no good reason.
Remark: To test this, playing with the DESTDIR variable is very useful
(this lets you install to a new directory (or the same as before)
without having to re-run the configure script). I used the following,
fairly slow shell script to collect permissions:
for f in $(find $DESTDIR); do \
echo $(basename $f) $(ls -l $f | cut -d' ' -f1); \
done | sort
Remark: it is important to run `sync` in-between 'make install' runs
to avoid timing effects due to filesystem or disk caching
strategies. I believe that this corresponds to the natural time delay
(and unrelated disk activity) that would occur in realistic
change-install-test feedback loops.
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These changes need to mature on their own branch.
git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14329 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
(Patch by Adrien Nader!)
Rev 14168 (build: replace ocamlcomp*.sh.) broke "make world" (but
surprisingly, not "world.opt") because the argument to ocamlmklib's -ocamlc
has to be a Windows path, i.e. C:\...\ocamlc. Instead it gave a UNIX one,
i.e. /home/foo/ocaml/ocamlc.
Call cygpath in otherlibs/Makefile.nt to fix that.
git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14175 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
This script was built from ocamlcomp.sh.in through sed and is called
instead of "ocamlc" (for instance).
It makes it possible to switch from "ocamlc" to "ocamlc.opt" without
changing anything in the Makefiles, only calling sed.
I couldn't cleanly make it handle both a compiler for the target and for
the build. Instead I'm replacing it and doing as much as possible
directly in the Makefiles.
I hoped it would reduce the number of shell invocations, which would
speed things up quite a lot on Windows but I still had to have at least
one since it's not possible to update a make variable from inside a make
rule: i.e. it's not possible to do X=a, build a.opt and update X to be
a.opt.
git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14168 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Nicolás Ojeda Bär
Gabriel Scherer
David Allsopp
Sébastien Hinderer
Mark Shinwell
hendriktews
Damien Doligez
whitequark
Damien Doligez
Alain Frisch
Xavier Leroy
Wojciech Meyer